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Old 11-10-2012, 06:38 PM   #1
apt13 OP
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Timing question

I got a wild hair up my butt last week and decided to do a big tune up and check/reset everything. I've become fairly well versed in adjusting my own valves, points, carbs, etc. but I've never been able to get a grasp on the timing. So I've got the valves set correctly, points gapped properly. But I can't figure out the timing. With the light gun I can't ever see the S mark no matter how I adjust the plate. I DO have the F at around 2500-2800 RPMs though. I've also tried to do it static with a buzzer, but it just constantly buzzes, no matter how I turn the rotor. I even had an electrician buddy help me with it and it just constantly buzzed.

Now the thing is,as far as I know, the bike seems to run just fine. I am just upset that I am not "learning" how to adjust the timing properly. Haha.

Is this something I need to worry about or just forget and be pleased with a well running bike?
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Old 11-10-2012, 08:59 PM   #2
supershaft
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Make sure your flywheel is put on right (OT at TDC) and then look into your advance. While I have seen very little advance troubles with bean cans, I see it semi-regualrly with points and typically work with a lot more bean cans. Rusted? Sticking? Sloppy worn out junk? Sounds like you need new springs too. The F mark shouldn't come up till later.
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Old 11-10-2012, 09:39 PM   #3
disston
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So I looked at your profile. You have a 1978 R80/7. This is the points not in a can but on a plate. Do you have a Booster or any other modification to the ignition?

You don't have to make the buzz box sound by setting the plate. Turn the alternator bolt to rotate the engine and see where the box goes on. It is the moment of sounding after being off that s the point of ignition firing. I prefer a static light myself. But it is the same thing. When the light comes on after being off is the point of firing. Guesstamate where it is firing. Way before the S? Close to the S?

The location slots in the timing plate can be elongated a little but this is probably not too Kosher. I usually find that if I can't get the timing right I don't have the gap right.

You are setting the timing, is this with new ignition points? How old are these points?

If the springs of the advance unit have never been changed they probably need it.
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Old 11-11-2012, 06:29 AM   #4
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ok, yes, the bike is a '78 R80/7. roughly 70k-ish miles as far as the odometer says. it's got points with no extra mumbo jumbo added.

the points are fairly new and still look to be in good shape. the timing advance unit is new-to-me/used and the springs on it are new. it seems to be working fine. i replaced it last year as the original one busted.

to be more specific with what i am doing, i have the front cover off, i've got an allen wrench in the rotor and i am turning it clockwise to get the S marks and everything to show. when i attach the buzz box (to the condenser plug and to earth) the buzzbox constantly buzzes. it does not matter how much i turn the rotor, it never stops buzzing. i didn't have a static light handy to test it with, but i guess i could make one easily. just to see if it stays lit the whole time. thats what had me perpexed though like i was doing it wrong.

so i took it to my buddy's garage who has a timing gun. that's when we tried to do it all by the gun and could never get it to show the S mark. we could adjust the plate and get the F at 2500-2800 rpms, and we could move that F up and down by turning the points plate, but no matter where we turned it, we could never get the S mark at idle (or anywhere).

so for now i just left it to where i get the F at 2500-2800. gapped the points. balanced the carbs. and it "seems" to ride just fine (as far as i know).
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Old 11-11-2012, 07:07 AM   #5
disston
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You may need a new set of points and condenser but that doesn't really seem to be the current problem. Modern day points do not last as long as they used to. The Tungsten coating is not as thick. We had a problem a couple years ago with the ignition points coming from the dealers didn't even work in most cases.

Aha ! You changed the advance unit. What are the last three digits of the number stamped into the top of the advance unit? I'm guessing here but I think yours should be 012. A 007 will work but you should not have a 005. (I'm not too sure of that info, look on Snowbum's site for the correct info or if you can't find it ask and I'll find it for you) Did the advance unit come from another R80/7 so you are pretty sure it is correct?

Did you grease the cam spindle the advance unit fits on? A light oil will work. What ever you use do it lightly. With the cover off and the bike running it is fun to watch the advance unit weights working. They are tight at idle and spread out as you rev the engine. All looks as it should?

There is a special grease for the points cam. I'm talking about the cam area the rubbing block of the points rides on. The rubbing block is a composite non-metallic material that opens the points as the cam rotates. This grease is very thick so it resists being flung onto the electrical contact area, which would ruin the points. The particular brand we have used for years is not easy to find, may not be available anywhere. It is Bosch Grease FT1V4. You can get a suitable substitute at a NAPA store. Just ask for "points contact grease". They may have to order it but they can get it. It's an Echlin product, that's their in house brand I think, and it has a part number something like E-1 or ML-1 or M-1.

If you can't find this or another points cam grease use a very thin coating of your regular grease on the cam and on the felt pad that keeps the cam wet.

I've never used a buzz box.I think they do the same thing as a continuity light. The light or the box must go out and then come on. If it's not doing this you are not hooking it up correctly. You have done the most important thing by setting the total advance to the F mark. Some advance units will have different amounts of total travel so they don't always work on the S mark at idle but the F mark is really more important.

Racers custom build the advance unit to get more performance. You could have one of these. What the racers usually do is braze a small amount of copper colored material in the hole at the top of the advance unit that you see the spring pins sticking through. They then finish the hole so it is smaller than it used to be. An advance unit like this will be set to still have the total advance where it needs to be at 2,500 rpm but it doesn't idle at the S mark. This could be what's happening. But we are not sure yet. Is there a copper color around the holes in the top of the advance unit? This is only one way to do this. It can also be done by peening the top part. This will leave sharp indentations around the holes?

Maybe the Buzz Box is the problem? Make a test light. I guess.
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Old 11-11-2012, 07:21 AM   #6
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thanks for the reply.

as for the numbers on the advance, i can't remember specifically what they are off the top of my head, but when i replaced it, i did do a lot of "research" and made sure i got the correct one. i remember there were 2 different kinds (numbers) and i did find the correct one i needed (used), and i did replace the springs and little washers on it with new ones.

and yes i did use the correct grease and such when i replaced it. and on the points.

i used 2 different continuity "buzz" testers and they both did the same thing. continuous buzzing.

i noticed that the haynes book tells you to turn the key on when testing, and the clymers book doesn't mention that, but i tried it both ways and still got the same result.

i suppose i could try new points and condenser, but to be honest, the bike seems to be running fine and i know the less i touch and fiddle with it, the less chance i will screw something else up. haha.

i think right now i'm just curious why it's doing what it does. or if someone chimes in with a "OH MY GAWD ITS GOING TO BLOW UP IF YOU RIDE IT LIKE THAT" i'll look more into "fixing" it.

oh yeah, and as for the TDC/OT for the flywheel. i'm not sure exactly how to make sure it's on correctly, but it matches up when i'm adjusting the valves.
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Old 11-11-2012, 07:48 AM   #7
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What SS mentioned is checking the position of the mark against where the piston actually is. It's fairly simple to do if done correctly but can damage the engine if you do it incorrectly.

There are 5 bolts holding the flywheel on. This means there are 5 different positions the flywheel can be in. Since your bike times at the F mark we don't really suspect this is a problem but I will quickly cover it just to give you something to do and it may be instructive, which I think you were looking for.

Front cover off so you can turn the engine with the alternator bolt. Engine in neutral, Both spark plugs out. Ignition off.

You need a plastic drinking straw or a chop stick from last nights Chinese dinner. (I like using the chop stick) Do not use some kind a a stick found on the ground that may break. The plastic straw will bend and not break. And the chop stick will not break.

The stick is placed into the spark plug hole and held with the right hand against the top of the piston. The engine is rotated with the left hand and the timing window is watched so that when the stick indicates the piston is at the top of it's travel the OT mark is in the window. You do not have to find exact TDC. It can be found using this method when needed. Rock the engine back and forth. Look for the OT mark. Note where the sick rises and then starts to fall back into the cylinder.

Because the flywheel only has 5 positions it can be in there is only one that is correct. The next nearest position to a correctly installed flywheel is 72* off. This will be very evident, very fast, using this method of finding TDC. This method is accurate to 1 or 2 degrees.

The danger is in using the wrong sort of probe in the plug hole or trapping the probe in the cylinder. You have to use care handling the stick and keep it from being "pinched" by the rising piston or getting broken by spinning the crank to fast. Do not use a screwdriver or any other metal object for a probe. These can scratch the piston or cylinder wall.

We do see flywheels put back on incorrectly after a rear engine seal replacement and sometimes other repairs when the mechanic is just not paying close enough attention. I've done it myself.
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Old 11-11-2012, 07:53 AM   #8
apt13 OP
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cool.
i'll give that a shot in the near future to satisfy my curiosity. thanks!
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Old 11-11-2012, 03:59 PM   #9
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I think your buzz box is either defective or not hooked up right. I don't know buzz boxes tho. Try to do this with a test light, see what you get.
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Old 11-12-2012, 02:39 PM   #10
supershaft
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I use to always TIG weld the advance. Brazing is too soft and wears too quickly IMO.
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Old 11-12-2012, 02:44 PM   #11
disston
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Quote:
Originally Posted by supershaft View Post
I use to always TIG weld the advance. Brazing is too soft and wears too quickly IMO.
Always the man to go one step more.

I made a stock advance unit from one that some racer had brazed up. I filed with a small round file until I had a stock advance curve. So There!
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Old 11-12-2012, 02:54 PM   #12
supershaft
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You would get done a lot quicker with a die grinder on one I set up! That braze is like butter comparatively speaking!
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Old 11-12-2012, 03:02 PM   #13
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Well I didn't want to cut it too fast. I did a little bit one day and then a little more day two. Then I was done. A grinder would probably mean having to braze again.

My bike seems happy for the most part. Rode almost a hundred miles today. It was unfortunately too warm. I'm ready for some colder weather.
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Old 11-13-2012, 01:56 AM   #14
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I had one recently (a customer's bike) where the points had just been replaced and could not see the timing marks. I had to readjust the point gap very carefully for the amount of drag and then could see the marks. The gap was just a bit too wide.
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